MEXICO CITY (EFE).- A dozen vertical gardens featuring a broad selection of different plants will decorate the sides of Mexico City's main thoroughfares beginning next year, adding a touch of green to this notoriously polluted city of 19 million inhabitants, organizers of the project said.

More than 15 fern species and an ample variety of plants and flowers are to be placed on some signs and billboards situated alongside highways and atop buildings.

The goal is to create environmental awareness and promote sustainable development, according to the heads of the groups sponsoring the initiative - the environmentalist organization VERDF and the Grupo Rentable company, which rents outdoor advertising space.

Industrial growth, a demographic explosion in recent decades (the population has grown from 3 million in 1950 to almost 20 million at present) and the proliferation of automobiles all contribute to making the air quality of Greater Mexico City among the worst in the world, experts say.

Under the slogan "Green-On", VERDF and Grupo Rentable on Wednesday inaugurated the first of these ecological murals alongside a busy road in Mexico City's Napoles neighborhood.

The large vertical garden, titled "El Hecho", covers a 41-square-meter (441-square-foot) area and is inspired by a fragment of the mural "La Marcha de la Humanidad" (The March of Humanity) by Mexican painter David Alfaro Siqueiros (1896-1974), the architect responsible for the work, Fernando Ortiz Monasterio, told Efe.

The garden is made up of different Mexican fern varieties in red and green hues and is meant to be appreciated by both pedestrians and car drivers alike.

"More than just an artistic undertaking, we want to offer a glimpse of the future of cities; it's a living system that has an important environmental benefit. It's important to integrate them (vertical gardens) for (better coexistence) within cities," Ortiz Monasterio said.

To mitigate the capital's environmental problems, the Mexico City government has been implementing a plan in recent years to combat pollution and promote sustainable public transportation.

Last year, it launched the Sustainable Housing Units initiative, which includes installation of solar panels, rainwater filters and vertical gardens on walls.

"It's not just a government issue but one of awareness and responsibility on the part of all society," VERDF's director, Gabriela Rodriguez, said.

"The goal of having vertical gardens in different parts of the city is to intervene in the public space with a fresh and living language, giving a small breath of fresh air to the city, both in the environmental and aesthetic sense," Rodriguez said.

She added that at the beginning of January the second of these vertical gardens will be placed along Pino Suarez Avenue, in the capital's historical center.

Mexico City accounts for 1.5 percent of the country's greenhouse gas emissions, while the capital's severe air pollution problems are blamed for aggravating respiratory illnesses and causing an estimated 4,000 deaths per year. EFE